"Microfilm frame", as the term is used herein, means a frame or frames of microphotography separated from a strip of a large number of such frames, wherein the frames are originally connected to one another. A common and established means for storage and later viewing of these frames is to place them in transparent jackets through which the images on the frames can be projected. The jackets have a top layer and a bottom layer joined at spaced regions to provide internal channels to receive microfilm frames. A slot is formed in one of the layers at each channel. The objective is to insert the frames singly or in groups through the slots into selected channels. Each frame can then be viewed by projection through the jacket on a reader device.
Inserter mechanisms for microfilm frames are known and are widely used. As they presently exist, they involve some disadvantages which if corrected can lead to substantial savings.
One such disadvantage is the wastage of film which arises from distributing microfilm frames from film strips. Movement of a film strip, and for that matter, film stored on a reel, requires pinch rollers which necessitate at the end of each segment, that there be a "tail" of substantial length. These tails constitute a surprisingly large wastage of film stock, especially on strips which may have only ten frames, and a tail length of perhaps 30% of the total strip length.
In addition, the movement of the frame along the channel is usually caused by being pushed by film behind it. Then the accuracy of positioning may be a function of skillful manipulation of the pinch rollers, rather than by an independant and readily manipulable device.
It is an object of this invention to provide insertion means which requires, at the most, a negligible tail, and which can accurately position one or more frames in a channel by the use of a device which is separate from the film itself.